Red Hat Security Advisory: xorg-x11-server security update
🔗 CVE IDs covered (8)
📋 Description
CVE-2026-88812 — xorg-x11-server: xwayland: xorg-x11-server: Arbitrary code execution via double-free in XKB geometry handling CVE-2026-93516 — xorg-x11-server: xorg-x11-server: Arbitrary code execution via use-after-free in passive grab handling CVE-2026-93517 — xorg-x11-server: xorg-x11-server: arbitrary code execution via GLX RenderLarge heap-based buffer overflow CVE-2026-93518 — xorg-x11-server: xorg-x11-server: arbitrary code execution via integer truncation during keyboard mapping resize CVE-2026-93519 — xorg-x11-server: xorg-x11-server: Arbitrary code execution via buffer overflow in input_constrain_cursor() CVE-2026-93520 — xorg-x11-server: xorg-x11-server: arbitrary code execution via out-of-bounds write in XKB keycode handling CVE-2026-93521 — xorg-x11-server: xorg-x11-server: Privilege escalation via crafted RandR provider property requests CVE-2026-93523 — xorg-x11-server: xorg-x11-server: Out-of-bounds write via unvalidated modifier in ProcXIPassiveUngrabDevice
🎯 Affected products96
- Red Hat Enterprise Linux AppStream (v. 8)
- Red Hat Enterprise Linux CRB (v. 8)
- xorg-x11-server-0:1.20.11-28.el8_10.5.src as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xdmx-0:1.20.11-28.el8_10.5.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xdmx-0:1.20.11-28.el8_10.5.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xdmx-0:1.20.11-28.el8_10.5.s390x as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xdmx-0:1.20.11-28.el8_10.5.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xdmx-debuginfo-0:1.20.11-28.el8_10.5.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xdmx-debuginfo-0:1.20.11-28.el8_10.5.aarch64 as a component of Red Hat Enterprise Linux CRB (v. 8)
- xorg-x11-server-Xdmx-debuginfo-0:1.20.11-28.el8_10.5.i686 as a component of Red Hat Enterprise Linux CRB (v. 8)
- xorg-x11-server-Xdmx-debuginfo-0:1.20.11-28.el8_10.5.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xdmx-debuginfo-0:1.20.11-28.el8_10.5.ppc64le as a component of Red Hat Enterprise Linux CRB (v. 8)
- xorg-x11-server-Xdmx-debuginfo-0:1.20.11-28.el8_10.5.s390x as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xdmx-debuginfo-0:1.20.11-28.el8_10.5.s390x as a component of Red Hat Enterprise Linux CRB (v. 8)
- xorg-x11-server-Xdmx-debuginfo-0:1.20.11-28.el8_10.5.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xdmx-debuginfo-0:1.20.11-28.el8_10.5.x86_64 as a component of Red Hat Enterprise Linux CRB (v. 8)
- xorg-x11-server-Xephyr-0:1.20.11-28.el8_10.5.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xephyr-0:1.20.11-28.el8_10.5.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xephyr-0:1.20.11-28.el8_10.5.s390x as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xephyr-0:1.20.11-28.el8_10.5.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xephyr-debuginfo-0:1.20.11-28.el8_10.5.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xephyr-debuginfo-0:1.20.11-28.el8_10.5.aarch64 as a component of Red Hat Enterprise Linux CRB (v. 8)
- xorg-x11-server-Xephyr-debuginfo-0:1.20.11-28.el8_10.5.i686 as a component of Red Hat Enterprise Linux CRB (v. 8)
- xorg-x11-server-Xephyr-debuginfo-0:1.20.11-28.el8_10.5.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xephyr-debuginfo-0:1.20.11-28.el8_10.5.ppc64le as a component of Red Hat Enterprise Linux CRB (v. 8)
- xorg-x11-server-Xephyr-debuginfo-0:1.20.11-28.el8_10.5.s390x as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xephyr-debuginfo-0:1.20.11-28.el8_10.5.s390x as a component of Red Hat Enterprise Linux CRB (v. 8)
- xorg-x11-server-Xephyr-debuginfo-0:1.20.11-28.el8_10.5.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- xorg-x11-server-Xephyr-debuginfo-0:1.20.11-28.el8_10.5.x86_64 as a component of Red Hat Enterprise Linux CRB (v. 8)
- xorg-x11-server-Xnest-0:1.20.11-28.el8_10.5.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
- +66 more not shown
✅ Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Workaround: On server systems where a graphical desktop interface is not required, exposure can be mitigated by disabling the graphical display manager or removing optional X11/Xwayland packages. To disable the graphical interface and boot into text mode: ``` systemctl set-default multi-user.target systemctl isolate multi-user.target ``` Alternatively, remove the affected packages if graphical sessions are not utilized: ``` dnf remove xorg-x11-server-Xorg xorg-x11-server-Xwayland ``` Caveats: Removing these packages or switching system targets will disable graphical login, may remove GNOME and related desktop packages via package manager dependencies, and will break graphical desktop functionality. The server will remain fully accessible and usable via local console terminals and remote SSH sessions. Warning: Executing these commands will immediately terminate all active graphical sessions. Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
🔗 References (11)
- selfhttps://access.redhat.com/errata/RHSA-2026:89747
- externalhttps://access.redhat.com/security/updates/classification/#important
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2545161
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2545164
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2545174
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2545177
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2545246
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2545860
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2545887
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2545908
- selfhttps://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_89747.json